Fixation of nitrogen



l atented at... 15, 1924, UNITED Banana-r n. uosns, or wasnm'e'ron, ms'rmcr or consume.-

FIXATION OF NITROGEN.

80 Drawing.

To all whom it may concern:

Be it known that I, Harman's B. Moses, a

: citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in the Fixation of Nitrogen, of which the following is a specification.

This invention relates to the fixation of nitrogen; and it comprises a method of fixing nitrogen wherein the. liquid nitrogen of liquid air is utilized as a source of nitrogen, heat and chemical reaction being 10- cally developed in, or in proximity to, a body of liquid comprising liquid nitro en wherein the products of reaction are ta en up, as in forming nitrogen oxids bythe local production of high temperature in, or in proximity to, a body of liqui'd air; all as more in ly hereinafter. set forth and as claimed.

In the fixation of nitrogen as nitrogen oxids or as ammonia, it is usual to resort to high pressures to obtain a high concentration of nitrogen in the reaction space, or to use high temperatures to facilitate reaction. Sometimes both high pressure and high temperature are simultaneously used. A

' In the present invention I depart from this practice and obtain a high concentration of nitrogen by liquefying it. In liquid nitrogen the concentration of nitrogen is greater than can be obtained by any commercially practicable pressure exerted on.the gas. The'same is true of li uid air which contains around 80 per cent 0 nitrogen. In a liquid mixture of nitrogen and hydrogen, the concentration of nitrogen is greater than can be conveniently obtained by pressure a one.

Combination of gaseous oxygenand gaseous nitrogen takes place freely at high temperatures; but the products of oxidation tend to dissociate again; that is, in cooling down from these hlgh temperatures to the ordinary temperature, the oxygen and nitrogen tend to brevert toatheir elemental form. This is a well recognized'fact in the various arc processes of-producingnitrogen oxids; processes in which air is momentarily subjected to the high temperature of the are. In these processes simple atmospheric cooling is enerally relied upon for the desired rapid through the dangerous temperature ranges.

In one-embodiment of the present invention I form oxidation products of nitrogen Application fllcd ltarch 6, 1919. Serial No 280,761.-

producing an intense heat of uniting with said nitrogen cooling of the are productslocally within, or in near proximity to, a body of liquid 1 air; the volume of liquid air being so great that as part of the liquid is used up, other -liquid will flow towards the locus, area or zone of heat to take its place. In so doing,

the products of oxidation formed at the high temperature are instantaneously chilled by the liquid air; passing swiftly through the dangerous ran e of temperatures mentioned.

As long as suc an action, that is, local high heating in the presence of liquid air, can

be obtained, the precise ratio of volumeof l1qu1d air to that undergoing reaction 1s, of

course, not essential; but it is commonly most convenient to use a relatively large volume of the li uid. The localized high temperature may e produced under, at or near the surface of the body of'liquid air.

The source of heat used in the described pgrocess may be varied. For example, it may an electric current passing through a suitable resistance body; this resistor' being either a first or second class conductor. Or there may be employed an electric spark or an 'electrlc arc. Heat may be chemically developed by the oxidation, at the expense of Hart of the oxy n of the liquid air, of oxiizable or com ustible material. On the whole, however, I find some t pe of electric heat most applicable, as it ena les more convenient local zation of the zone or locus of high tem eratures; ,In using combustion heat, special precautions must be taken to avoid explosion. I I

The, described method may also be conveniently used in the. production of NH from liquid mixtures of nitrogen and hy- ;drogen.-- Y

Liquid air can be employed, but in this event some of the oxygen combines with the hydrogen and I re rd it as better to use liquid nitrogen or nitrogen-rich liquids produced in the liquefaction of air.

1. The process of-forrning a normally gaseous' nitrogen -.com ound which comprises subiecting a liqui body consisting essential y of iquid nitrogen and'a bodfy capable to orm gaseous nitrogen compounds to a locus of high heat.

2. The process of forming normally gaseous nitrogen com ounds which comprises subjectin a liquid body consisting essentially of lquid nitrogen and another element 10 pounds to a source capable of uniting with said nitrogen to form gaseous nitrogen compounds to a source of high heat.

3. The process of forming normally gaseous nitrogen compounds which comprises subjecting continuously a liquid body consisting essentially of liquid nitrogen and an other element capable of uniting with said nitrogen to form aseous nitrogen comhigh heat.

4. The process of forming nitrogen oxides which comprises subjecting a body of liquid vconsisting essentially of nitrogen and oxygen to a locus of high heat.

5. The process of forming nitrogen oxides which comprises subjecting continuously a body of liquid consisting essentiallypof nitrogen and oxygen to a locus of high heat.

6. The process of forming nitrogen oxides which comprises contacting a liquid body consistin essentially of liquid air with a locus of high heat.

7. The process of forming nitrogen oxides which comprises contacting a body of liquid consisting essentially of nitrogen and oxygen with a source of high heat.

8. The process of forming nitrogen oxides which comprises contacting a liquid body consisting essentially of liquid air with a source of high heat.

9. The process of combining elemental nitro en with another element to form a norna ly gaseous compound which comprises maintaining a source of high heat in contact with a liquid mixture consisting essentially of nitrogen and the other element.

HERBERT B. MOSES. 

